This invention relates to a novel hot water space heating system and apparatus.
Space heating systems of the hydronic variety have become more and more popular due to the quality of the radiant heat, uniformity of heat distribution, and other reasons. Common radiant heating systems include circulating heated water through coils which are placed within floors, ceilings or along baseboards. The coils are often assembled in the form of panels which may be laid within concrete and/or wooden floors and ceilings. Typically the systems use a heating vessel or boiler coupled with a pressurized supply of water. The pressurized system requires use of several components for pressure reducing, air venting, water expansion and tempering and other items necessary to deal with the pressurized source. Water pressure reducing valves are commonly used to change the supply water pressure to system operating pressures. City supply water pressure is approximately 70 p.s.i., and typical well water pump pressure is approximately 45 p.s.i. Normal system operating pressure is approximately 12 to 15 p.s.i., thus requiring pressure reducing components.
In order to circulate the water, air pockets or bubbles must be bled from the radiant coils or panels, otherwise the circulator would lock up with an air gap and would not be able to route the heated water throughout the dwelling or location which is to be heated. Such systems are pressurized and sealed so that air pockets and bubbles are eliminated; Installation and sealing of such a system is problematic, and use of components under pressure can result in extra stress on the components resulting in shortened product life.
Were the pressurized system to lose its seal or to have not been properly bled, the installation would require repeated sealing. Common maintenance to the system may also require resealing.
Pressurized water sources are not always available. In remote areas which do not have pressurized water, the radiant heat method is largely unavailable. Further, a pressurized system presents additional danger where the water is heated under pressure and passed through various components which are designed to handle and temper the pressurized water. While such components for handling pressurization are designed to handle specified loads, the need for such components would not be present if there was no pressurization. Accordingly, the cost of the entire system can be lessened if concerns over pressurization are eliminated.
In the past, another common variety of radiant type heating system was an open system which used a heating vessel or boiler, and also required a constant or manual source of water supply. Such systems required constant air removal methods and oxidation reduction treatment. Bleeding of the radiators was typically required in such systems. Hydronic systems historically used only gravity to move the heating water (i.e., hot water rises to radiators while the water returns as it cools). Such system required very high temperature to create this effect (180 to 200 degrees Fahrenheit) and required very large piping and radiators to transfer the heat. Such system required a large tank to handle water expansion, and required frequent filling and monitoring of the water level due to evaporation. Further, such system required a configuration where the heating vessel was positioned at a point beneath the heating radiators, while the expansion tank was to be positioned at the highest point above the heating radiators. Such open type system also used a vent that usually exited the top of the building for release of air and vapors. The system vent was capable of freezing in cold climates. The vent had to be higher than the highest radiator of the system to allow air to escape and usually was configured through an attic to the outside environment. Special treatments were also required to be added to such system to retard corrosion of piping caused by the oxygen in the system due to the frequent addition of supply water.
Applicant has been unable to locate a non-pressured, self-contained hydronic system. Providing such a system can eliminate the overall cost of the system and reduce efforts in installation while also eliminating the concerns of pressure, treatment, and sealing. Providing efficient radiant heat to locations which do not have a pressurized water source is a further goal. Moreover, the historic non-pressurized systems have become obsolete since they are too bulky, require continued monitoring, and operate at very high temperatures. Applicant has invented a practical non-pressurized space heating system which utilizes a conventional type of water heater.
While applicant has found several attempts to utilize water heaters for a variety of combination purposes (see for example U.S. Pat. Nos. 4,848,655; 4,925,093; 4,946,098; 5,039,007; 5,076,595; 5,361,751; 5,372,185; 5,485,879; 5,573,183; 5,707,007; Foreign Patent No. 8702-649-A; Foreign Patent No. WO 90/02300; and Foreign Patent No. 2,657,951), applicant is unaware of any non-pressurized radiant heating system of the type described herein.
It is an object of this invention to provide a radiant heating system which does not require a pressurized water source.
It is another object of this invention to provide a radiant heating system that utilizes standard glass-line, direct-fired, gas water heaters.
It is still another object of this invention to provide a radiant heating system which is self-contained that does not need a replenishing water supply.
It is a further object of this invention to provide a radiant heating system characterized by both low manufacturing cost, maintenance cost, versatility, and portability.
It is a further object of the invention to provide energy savings in the form of utilizing previously heated water already contained within the tank.
Other objects and advantages of the present invention will become apparent to those skilled in the art from the drawings, the detailed description of the preferred embodiments and the claims.
The non-pressurized heating system comprises a standard heating vessel or water heater for heating the water to be circulated throughout the radiant coils. The coils connecting to the piping of the heating system are laid throughout the flooring, along baseboards or ceiling area for space heating. The radiant heating coils reconnect with the piping so the water which had circulated and has now become cooler returns to the heater to be heated for reuse and recirculation. The water heater is positioned above the coils. The system includes a means for releasing air contained within the piping. In a specific embodiment the system includes an isolation or auxiliary ballast or container which holds liquid and operates to impart an atmospheric pressure and seals the self-contained system. Air pockets or bubbles throughout the radiant coils eventually work their way through the system to the releasing means for release to the atmosphere. Such venting prevents air lock in the system, which otherwise might typically cause a circulating pump to fail. A conventional water heater can be configured to accommodate the system. The usual relief port of a conventional water heater is utilized as the radiant coil supply line. The cold water inlet of the typical water heater receives the return from the radiant coils. The typical hot water port of the water heater is connected with the isolation ballast.
The liquid heater apparatus of the present invention includes a heating tank to contain a liquid, a gas burner positioned to heat the liquid, a supply port from which heated liquid may be supplied to circulating coils which are laid throughout the space to be heated, a return port to which liquid is returned from the coils, and a releasing means for releasing air contained within the liquid heater. In a specific embodiment the apparatus includes an isolation ballast located above the water heater. The isolation ballast provides atmospheric isolation between the atmosphere and the water contained in the system. The isolation ballast also operates to allow venting of air from the connected coil system. The apparatus includes a modified conventional water heater described above, and connects with coil systems to circulate fluid and provide radiant heat. The apparatus is incorporated into radiant heat systems; and multiple apparatus and systems may be used together. A separate apparatus and/or system may be used to provide radiant heat to separate levels in a dwelling or structure. Multiple systems can be combined as needed, to supply heat to larger single-level flooring areas, or numerous levels. A further embodiment includes use of an apparatus similar to that described above yet including a coil unit. With use of a combined coil unit, the apparatus is versatile for use in numerous locations.